A new method for analysis of Multi-State systems based on Multi-valued decision diagram under epistemic uncertainty

Seafarers’ unsafe acts as the direct causes of maritime accidents are considered to be the result of the interaction between complex and dynamic influencing factors. Identifying the risk evolution characteristics and paths of seafarers’ unsafe acts has always been a challenge in maritime safety management. For this purpose, the present study introduces association rule technique into complex network to develop a directed weighted interaction network of seafarers’ unsafe acts and their influencing factors. Through global network topology analysis and local network community detection, the risk evolution characteristics of seafarers’ unsafe acts in maritime accidents are analyzed from a multidimensional perspective. The results indicate that the developed network has small-world characteristics, and the top 10 critical nodes all belong to seafarers’ unsafe acts, of which failure to make proper sound and light signals achieves the highest PageRank value. Results from this study would help maritime stakeholders to understand the evolution mechanism of seafarers’ unsafe acts and develop safety management strategies for interrupting the risk propagation of seafarers’ unsafe acts.

Section: Discussionmentioning

confidence: 99%

Risk Evolution Analysis of Seafarers’ Unsafe Acts in Maritime Accidents Based on Directed Weighted CN

Lan,

2024

“…At t 1 , the excitation currents i Lm1 and i Lm2 of the forward converters can be calculated by (10):…”

Section: Circuit Analysismentioning

confidence: 99%

“…Consequently, its diagnostic results always depend on highly reliable mathematical models and analysis methods. The mathematical models and analytical methods proposed in [8][9][10] can be applied to SOH to improve the reliability and accuracy of its diagnostic results. For healthy lithium-ion batteries, battery balancing techniques are usually employed to address the inconsistency of cells in the battery pack [11,12].…”

Section: Introductionmentioning

confidence: 99%

Multi-Mode Lithium-Ion Battery Balancing Circuit Based on Forward Converter with Resonant Reset

Zong,

Li,

Wang

et al. 2023

A multi-mode active balancing circuit based on a forward converter with resonant reset is proposed to deal with unbalanced states of lithium-ion battery packs. The balancing circuit utilizes the forward converter, enabling high-power balancing. SPST relays are selected to constitute the switching matrix, and the proposed balancing circuit completes the connection of serial battery clusters to the main circuit by controlling the SPST relays, realizing the Multi-Cell-to-Multi-Cell (MC2MC) balancing method. An “adaptive selection mode based on the state of high energy battery” balancing strategy is proposed. The proposed balancing strategy allows the proposed balancing circuit to have multiple balancing modes, flexible balancing paths, and switching between different balancing processes in real time, significantly improving the balancing speed. The inherent LC resonant reset structure of the forward converter is employed to achieve MOSFET zero-voltage switching (ZVS). To optimize the balancing performance, the circuit model is built and the balancing parameters in the circuit are analyzed. An experiment with an eight-cell lithium-ion battery pack was performed to verify the balancing effect of the proposed circuit, and comparison with a typical balancing circuit was carried out. Experimental results show that the proposed balancing circuit has a faster balancing speed.

“…The generated fatigue damage directly determines the component's reliability, replacement policy, and warranty costs. Thus, the reliability index characteristic has an important role that is determined mathematically and is used to describe the fatigue damage behavior of mechanical components [4]. That description can be performed by using a probabilistic approach [5].…”

Section: Introductionmentioning

confidence: 99%

Reliability by Using Weibull Distribution Based on Vibration Fatigue Damage

Barraza-Contreras,

Piña-Monarrez,

Torres-Villaseñor

2023

In this paper, a Weibull probabilistic methodology is proposed with an approach to model vibration fatigue damage accumulation using two parameters: Weibull distribution and a nonlinear fatigue damage accumulation model. The damage is cumulated based on the application of a vibration stress profile and is used to determine both the Weibull β and η parameters, and the corresponding component reliability R(t). The vibration fatigue damage is analyzed to accumulate the damage as a stress function for a fatigue life exponent derived with the assistance of the acceleration’s force response. The steps to determine the Weibull β and η parameters are estimated based only on the principal vibration stresses σ1 and σ2 that allow the reproduction of the vibration fatigue damage. The method’s efficiency is based on the probabilistic approach by using the vibration fatigue damage as the Yi vector that covers the arithmetic mean as well as the β parameter. Finally, the procedure proposed is applied in a practical case where a mechanical component is used as a support for telecommunication connections and is submitted to vibration stress. The results show that using the damage accumulated as the Yi vector to estimate the parameters allows for the analysis of dynamic and individual applications.